The concept of wireless speakers has existed for many years, however, due to less demands, this market sector is still embryonic, just like the case of tablet PCs. Nevertheless, with the rapid expansion of market shares of laptops, smart phones and tablet PCs in recent years, users' demand for enjoying high quality music anywhere without locational constraints is showing an increasing trend.
Currently, the wireless speaker market is primarily dominated by Bluetooth and WiFi products. The Bluetooth sector is more developed and there are many brands therein, including both foreign and domestic ones. On the other hand, the existing brands participating in the WiFi sector mainly include Air Play of Apple Inc. and several brands of Sony Corporation.
Between the aforementioned two wireless audio solutions, Bluetooth is undoubtedly more universal and has a longer history, from its earliest application in an earphone for Ericsson mobile phones. A predominant advantage of Bluetooth over WiFi is its low power consumption property—the mainstream Bluetooth 2.1 version is embedded with a feature called “Sniff Subrating” which allows distance-dependent transmission power adjustment for power consumption reduction. In addition, Bluetooth is also excellent in interference immunity and point-to-point communication security. Despite these advantages, Bluetooth does, however, suffer from some limitations, one of which is its insufficient data transfer rate (DTR). DTR of the earliest Bluetooth 1.x version was only about 748-810 Kbps, with which audio data had to be transmitted in a compressed form and the obtained acoustic quality rendered the technology only suitable for the application of voice communications rather than music playing due to significant acoustic distortion. Although the DTR has been greatly increased to about 1.8-2.1 Mbps in the current mainstream Bluetooth 2.1 version, it is still insufficient for lossless transmission of high-quality stereo data. Another limitation of Bluetooth is just its point-to-point nature, which, on one hand, makes the technology unable to establish a multi-room audio system as conveniently as the point-to-multipoint WiFi solution, and on the other hand, adds difficulty by requiring ever-successfully paired players to be re-paired for any new connection. Furthermore, although Bluetooth modules adopting the most popular Class B format generally has a nominal working distance of 8-30 meters, their actual effective distance (open space) is only about 10 meters, which is insufficient, in particular, for home use and the establishment of a multi-room audio system.
WiFi is the abbreviation of “wireless fidelity”, and its part “Fi” shares the same meaning with that of Hi-Fi (high-fidelity). While WiFi is inferior to Bluetooth both in communication privacy and interference immunity, it has better performance in terms of speed and networking. Taking the existing mainstream 802.11g and 802.11n standards as examples, their DTR's are 54 Mbps and 300 Mbps respectively, both far beyond the needed bandwidth for creating an acoustic quality that can be obtained by a CD player, and the excessive part can further support users' simultaneous activities, such as video contents transmission and webpage browsing. Moreover, in addition to paired connection between individual devices, WiFi further is capable of, as its most crucial advantage, wireless router-based networking. With this advantage of WiFi, an iPad connected to all speakers in a network by Airplay can accomplish the following mission that is impossible to be fulfilled by a Bluetooth counterpart: broadcasting audio to all the speakers, or only to certain ones of interest, and simultaneously allowing webpage browsing and other user activities. Such networking scheme is more popular abroad. For example, Sonos, who entered the China market last year, is one of the famous providers in the U.S. for WiFi audio solutions. While the domestic market for wireless multi-room audio systems is currently still in its infancy, we have observed increasing acceptance among high-end users.
As noted above, Bluetooth and WiFi both have their strengths and weaknesses. However, as they belong to different branches of the wireless technology, current efforts for their improvement are being exerted based on a technical bias that they should be developed separately along their own tracks. As a result of the efforts, we have found by searching several wireless speakers related technologies disclosed in recent years.
Referring to FIG. 1, Chinese Pat. Pub. No. CN102427570A discloses a wireless speaker with IR remote control functionality, as well as high-temperature and overload protection for its main control circuit. However, a problem with this speaker is that it is not suitable for use in wireless-free environments.
FIGS. 2-3 show a Bluetooth speaker system disclosed in Chinese Pat. Pub. No. CN102724609A, which achieves the combined use of multiple Bluetooth speakers. However, this system still has several disadvantages, such as for example, 1) it has to adopt a complicated control method for Bluetooth-based communications; and 2) it can only support a maximum number of only one satellite speaker.
Further, Chinese Pat. Pub. No. CN201995106U discloses a wireless speaker, as shown in FIG. 4, which is capable of establishing a wireless network by bringing together the functions of a WiFi speaker and a wireless access point (AP). This is a solution commonly employed in many products on the market. However, as the speaker just simply combines the roles of a WiFi router and a Bluetooth speaker into a single device and switches between the roles via a switch, it is unable to provide multiple operating modes.
It would therefore be advantageous to have a more ergonomic wireless speaker that has multiple functions and options to meet users' increasing requirements.